Cloud Foundry Logo
blog single gear
Security Advisory

USN-4660-2: Linux kernel regression

Severity

Unknown

Vendor

Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 16.04

Description

USN-4660-1 fixed vulnerabilities in the Linux kernel. Unfortunately, that update introduced a regression in the software raid10 driver when used with fstrim that could lead to data corruption. This update fixes the problem.

Original advisory details:

It was discovered that a race condition existed in the perf subsystem of the Linux kernel, leading to a use-after-free vulnerability. An attacker with access to the perf subsystem could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-14351)

It was discovered that the frame buffer implementation in the Linux kernel did not properly handle some edge cases in software scrollback. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-14390)

It was discovered that the netfilter connection tracker for netlink in the Linux kernel did not properly perform bounds checking in some situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-25211)

It was discovered that the Rados block device (rbd) driver in the Linux kernel did not properly perform privilege checks for access to rbd devices in some situations. A local attacker could use this to map or unmap rbd block devices. (CVE-2020-25284)

It was discovered that a race condition existed in the hugetlb sysctl implementation in the Linux kernel. A privileged attacker could use this to cause a denial of service (system crash). (CVE-2020-25285)

It was discovered that the block layer subsystem in the Linux kernel did not properly handle zero-length requests. A local attacker could use this to cause a denial of service. (CVE-2020-25641)

It was discovered that the HDLC PPP implementation in the Linux kernel did not properly validate input in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-25643)

It was discovered that the GENEVE tunnel implementation in the Linux kernel when combined with IPSec did not properly select IP routes in some situations. An attacker could use this to expose sensitive information (unencrypted network traffic). (CVE-2020-25645)

It was discovered that the framebuffer implementation in the Linux kernel did not properly perform range checks in certain situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-28915)

It was discovered that Power 9 processors could be coerced to expose information from the L1 cache in certain situations. A local attacker could use this to expose sensitive information. (CVE-2020-4788)

Affected Cloud Foundry Products and Versions

Severity is unknown unless otherwise noted.

  • Xenial Stemcells
    • 315.x versions prior to 315.204
    • 456.x versions prior to 456.131
    • 621.x versions prior to 621.95
    • All other stemcells not listed.

Mitigation

Users of affected products are strongly encouraged to follow the mitigations below. The Cloud Foundry project recommends upgrading the following releases:

  • Xenial Stemcells
    • Upgrade 315.x versions to 315.204 or greater
    • Upgrade 456.x versions to 456.131 or greater
    • Upgrade 621.x versions to 621.95 or greater
    • All other stemcells should be upgraded to the latest version available on bosh.io.

References

History

2021-02-10: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR

SEE ALL ARTICLES